Isolated dislocation of the trapezium.

A 31-year-old housewife attended the Accident and Emergency Department of the Mater Infirmorum Hospital, Belfast, Northern Ireland, having fallen and injured her left wrist. She had fallen backwards onto her outstretched hand, forcing the wrist into considerable dorsi-flexion with the forearm in supination. Examination revealed bruising and swelling at the base of the first metacarpal and over the thenar eminence. Movements of the thumb were painful. X-rays (Fig. 1) showed that the trapezium had been completely dislocated in a palmar direction. No fracture of surrounding bones had occurred. On the following morning closed reduction was carried out successfully, with the aid of an image intensifier. The hand and forearm were immobilized in a Bennet's type plaster cast which was removed after 6 weeks. Initially, movements of the thumb were somewhat stiff but the situation improved rapidly, and she was able to be discharged with a full range of pain-free movement and no continuing disability a few weeks later.